Retractable pack-off device



Jan. 4, 1944. G. GREEN 2,338,326

RETRACTABLE PACK-OFF DEVICES Filed'March 18/1940 4 Sheets-Sheet 2 v 3 r 620mm @955 Jan; 4, 1944. G. GREEN RETRACTABLE 'P ACK- OFF DEVICES 4 Sheets-Sheet 3 Filed March 18, 1940 N m G 5 m w P Patented Jan. 4, 1944 UNITED STATES PATENT OFFICE BETRAcTABL lfiil i- OFF DEVICE v bppllclt l l z s l l zz rflfzb 324,481

4 Claims.

This invention relates to new and useful improvements in retractable pack-oil. devices.

It is often desirable to cement a well bore below a. certain point, or to place a bridge plug of cement within a well bore. It is one object of this invention to provide a pack-off device suitable forv use in such instances.

Another object of the invention is to provide an improved pack-off device having means whereby the device may be lowered into a wellv bore in an inoperative position and adjusted to an operative position after it has been lowered to the point below which it is desired to cement the well bore. I

An important object of the invention is to proan improved pack-oft device in which any pressure existent in the well bore has no eilect upon the setting or releasing of said device, and wherein the unlatching of a J-slot or J-slots is not vide an improved pack-off device which may be I means from setting the anchoring means to such an extent as to deform the casing or prevent the unsetting of the anchoring means.

A further object of the invention is to provide an improved pack-off device which may be positively and easily set, said device having a shear pin disposed therein, whereby, in the event the device becomes stuck or lodged in the well bore, a portion of the device may be retrieved to the top of the well bore by shearing said pin, the remainder of said device being formed of drillable material so that it may be drilled out of the well bore to clear said bore. g

Still another object of the invention is to provide an improved pack-off devicehaving an axial support, a packer, pipe engaging elements, and

means for displacing said elements upon actua-' tion of said support, whereby the support may be moved longitudinally to displace said pipe ongaging elements into gripping engagement with the well casing, and then rotated to disengage the parts so as to leave the gripping elements in a set or anchoring position, and the support free for longitudinal movement to expand the packer.

Another object of the invention is to provide an improved retractable pack-off device so arranged that it may be utilized to retain cement while the latter is setting; also to wash above the cement, and which may be retrieved from the well bore after the cementing operation is completed.

A further object of the invention is to provide affected by fluid pressure present in the well bore.

Another object of the invention is to provide an improved pack-01f device having means whereby the packer may be lowered into a well bore in an inoperative position and adjusted to an operative position at the desired location, thereby packing oil. between the lower portion of the well bore and the upper portion, so that said well may be produced through said device.

A construction designed to carry out the invention will be hereinafter described, together with other features of the invention. I

The invention will be more readily understood from a reading of the following specification and by reference to the accompanying drawings, in which an example of the invention is shown, and wherein:

Figure 1 is a longitudinal view, partly in elevation and partly in section, of a pack-oil device constructed in accordance with the invention, showing the device in an unset position as it is lowered into the well bore,

Figure 2 is a similar view showing the device in a set position preparatory to the pumping of the cement down the well ,tubing,

Figure 3 is a longitudinal view, partly in elevation and partly in section, showing the device in a washing position, v

Figure 4 is a similar view showing the device in a partially disengaged or loosened position preparatory to the removal of said device from the well bore, I

Figure 5 is a horizontal, cross-sectional view taken on the line 5-5 of Figure 1,

Figure 6 is a horizontal, cross-sectional view taken on the line 5-6 of Figure 1,

' Figure 7 is a horizontal, cross-sectional vie taken on the line l-! of Figure 4,

Figure 8 is a horizontal, cross-sectional view taken on the line 8-8 of Figured, Figure 9 is a horizontal, cross-sectional view taken on the line 8-9 of Figure 4,

Figure 13 is a continuation of Fi ure 12.

In the drawings, the numeral III designates a cylindrical support housing formed of an upper sleeve II and a lower sleeve I2. -'I'he housing I8 is 'designed to be connected to a tubing string or other conductor (not shown) and-lowered into a well casing A. An elongate tubular mandrel I3 is disposed axially of the housing and has its upper end extending above the housing, and provided with suitable means for connecting the tubing string or other conductor with the device. The upper sleeve I I of the housing is provided with a, plurality of spaced longitudinal grooves I4 formed on its inner wall and extending from the upper end portion of said sleeve downwardly therefrom. An internal collar I6 has a sliding fit within the bore of the sleeve II and is formed exteriorly with a plurality of radially-extending, vertical lugs I6, said lugs having a. sliding fit in the grooves I4. The engagement of the lugs I6 in the grooves l4 renders the collar. I incapable of rotative movement with respect to the sleeve II. but at the same time allows the collar to undergo limited longitudinal movement within said .sleeve. A plurality of ordinary'friction shoes II are provided about the outer wall of the sleeve II Internal screw-threads I I are formed in the upper end of the sleeve II, and a bushing I8 has screw-threaded engagement therein with ,said screw-threads, the bushing I8 being provided with an axial bore I9 through which the mandrel I3 extends. A pair of diametrically-opposed, vertical grooves 20 are provided in the wall of the bore I9, and extend from the upper surface of the bushing I8 downwardly thereinto. A pair of diametrically-opposed, divergent, horizontal slots 2| are formed in the bushing and disposed so as the bushing, said slots communicating with the lower extremities of the grooves 28. A pair of diametrically-opposed radial grooves "are 'offset from the bottom of the slots 2| so as to be displaced 90 degrees from the verticalgrooves 20. It will be seen (Figures 5, 10, and 11) that the grooves 28. slots 2|, and grooves 22 form a pair of diametrically-opposed J-slots 23, the function of which will be disclosed hereinafter. A pair of diametrically-opposed, radially-extending pins 24 are-provided on the upper outer surface of the mandrel I3 so as to engagein the J-slots 23.

The lower extremity of the sleeve II is recessed and carries internal, left-hand screw-threads25 which are engaged by external, left-hand screwthreads 26 formed uponthe upper reduced end of the sleeve I2. It is pointed out that the reduced end of the lower sleeve telescopes the upper sleeve, whereby said sleeves are flush and present a substantially continuous inner and outer wall.

to extend from the bore I9 to the outer wall of A shear pin 21 passes transversely through the screw-threaded joint between the thus locking them together.

A plurality of rectangular radial openings 28 are provided in thewall of the sleeve I2, said openings being spaced slightly below the screwthreaded joint between the sleeve I2 and the sleeve II. A plurality of slips 29 aredisposed so as to have their gripping faces 30 projecting through the openings 28, while their rearward or inner faces 3| are inclined downwardly and have longitudinal dovetail grooves 32 formed therein. The gripping faces 38 of the slips 29 are made up of teeth so as to prevent upward .movement and rotative movement when engaging the inner wall of the casing A.

A slip actuating collar 33, having an axial bore two sleeves,

83', encircles the mandrel I3, and is provided exteriorly with a plurality of upright inclined faces 34 (Figures 1, 2 and 6) for receiving the inclined inner faces 3| of the slips 29. The collar faces 34 have longitudinal dovetails 36 complementary to and engaging the dovetail grooves 32 formed in the slips. The inclined faces of the collar and the dovetails when moved upwardly will cause the slips 29 to be displaced outwardly into gripping engagement with the inner wall of the casing A, and when moved downwardly will cause the slips to be retracted. It is pointed out, that the slips are free to move in these-directions only, since they are prevented from longitudinal or lateral movement by the walls of the openings 28.

The axial bore 33 has internal left-hand screw-threads 36 at its upper portion, said screwthreads engaging similar external ,left-hand screw-threads 31 formed upon the mandrel I3, whereby the collar 33 is supported and held in position by the mandrel. The upper collar I6 is provided with internal left-hand screw-threads 38 which substantially match the screw-threads 36 formed in the bore 33. It will be noted that the lower collar 33 is held against rotative movement by its dovetailed engagement with the slips 29 which are in turn held by the walls of the openings 28. The collar I5, being free to move downwardly, is supported by the engagement of the collar 33 with the screw-threads 31 and the slips 29. The supporting of the collar I5 by the collar 33, and the holding of both collars against rotation, allows ,the screw-threads 38 to be matched with the screw-threads 36 and form a continuation of the latter. In the position shown in Figure 1, the screw-threads 31, formed upon the mandrel I3, engage the screw-threads 36 formed in the collar 33, and the screw-threads 33 in the collar I5. An inwardly projecting pin 39 is positioned in the wall of the sleeve I2 at a point below the slip actuator or slip-actuating collar 33 so as tolimit the downward travel of said collar.

An inwardly projecting annular shoulder 40 is formed on the lower extremity of the sleeve I2, and a plurality of radial ports M are provided in the wall of said sleeve slightly above said shoulder. A tubular shank or hanger 42, having an end, is positioned so that the under side of the flange 43 engages the upper side of the shoulder 40, preventing longitudinal downward motion of the. tubular shank or hanger 42. The shank 42 is provided with a plurality of radial ports 44 spaced slightly below the flange 43, and is of such diameter that its outer surface has a sliding fit in the shoulder 40, thereby closing the ports 44; while the outer periphery of the flange 43 has a similar engagement with the inner wall of the sleeve I2 and thereby closes the ports 4| (Figure 1). It will be readily seen by an examination of the drawings, that upward movement of the shank 42 with respect to the sleeve I2 will cause both the ports H and the ports 44 to be uncovered, whereby communication is set up between the bore of the shank 42 and the annular space outside the sleeve I2.

Internal left-hand screw-threads 45 are formed in the lower end of the shank 42. An internal annular flange 46 is spaced upwardly from the screw-threads 45 within the shank, and has a sliding fit on the mandrel I3. A tubular head or plug 41 has an upstanding reduced pin 48 formed on its upper end, and provided with external lefthand screw-threads 48' and internal left-hand screw-threads 49. The pin telescopes the lower end of the shank and the threads 45 engage the threads 43'. Externalleft-hsnd screw-threads ID are provided upon the lower end of the mandrel l3 and engage the screw-threads 40. A plurality of radial ports II are formed in the wall of the mandrel l3 and spaced slightly above the screw-threads l and below the flange 43, when the device is lowered into the well. A resilient packing ring I2 encircles the mandrel l3 and is positioned immediately below the flange 43, thereby closing or shutting oi! communication through the ports ll.

The lower end of the head is enlarged and formed with an outwardly-directed, annular shoulder 53. A plurality of suitable elastic packing rings [I rest upon the shoulder surrounding the head and the shank. It will be noted, that the packing rings 54 are separated by suitable flat spacer rings 55. The packing rings engage the lower extremity of the sleeve i2 when the device is set and the rings are in a packed-of! position.

The head 41 is formed with an axial bore 53 which has a suitable poppet valve assembly 51 mounted inits lower end. The valve assembly 51 includes a valve 58 having an elongate valve stem extending upwardly through a spider 33 which is screwed into the bore 53. The upper end of the valve stem It has a nut 3i screwed thereon, and a suitable coil spring 32 is confined between said nut and the spider 33. The spring will constantly urge the valve upwardly into a seated position against a seat 33 on the bottom of the head. Pressure acting downwardly through the bore 58 will act upon the upper surface of the valve 58, to force the same downwardly against the compression of the spring 32, and open the valve.

In the operation of the device, the assembly is lowered into the well bore in the position shown in Figure 1. In this position, the pins 24 are engaged in the grooves 22, and the slips 29 are in a retracted position. When a suitable or desirable point is reached in the well bore, the mandrel I3 is rotated by means of the tubing (not shown) from which the device is suspended. The sleeve ll of the housing ID will be held against rotation by the friction shoes i I, while the mandrel is rotated anti-clockwise through 90 degrees. This rotation will unlock the J-slot mechanism and allow the pins 24 on the mandrel l3 to be moved upwardly in the grooves 20. Emphasis is laid upon the fact that any fluid pressure present in the well bore will have no effect upon the un-' latching 'of the J-slots. The upward movement of the mandrel i3 will force the collar 33 to move upwardly within the inclined faces of the slips 29, thus displacing the slips outwardly into engagement with the inner wall of the well casing A (Figure 2). Subsequent upward movement of the mandrel l3 will cause the collar 33 to move upwardly and press the slips into snug engagement with the inside wall of the well casing. The slips may be set as tightly as desired without affecting the movement of the mandrel through the bore 33' of the collar 33. It should be noted that the collar 33 is an annular member which will be wedged in between the slips and the friction of such wedging tends to retain the collar in position to retain the slips against the casing. The slips are set to the desired point at this step of the operation. Any pressure acting upon the packing rings will tend to engage them-more snugly with the wall of the casing A, but will not tend to set the slips any tighter.

when the slips have been set suillcientlytight. the mandrel is rotated clockwise. The lower portion of the device, including the packing rings and the shank I are free to rotate with the mandrel. However, the upp r portion including the housing is held against clockwise rotation by the action of the gripping faces 3|! of the slips. Therefore, the screw-threads 31 on the mandrel will unscrew from the screw-threads 36 in the collar 33, and will screw into the screwthreads 33 in the collar I. This is possible, because, as pointed out hereinbefore, the screwthreads 33 and 31 are held in a matched position due to the incapability, of the collar 33 and the sleeve II to undergo rotative movement with respect to each other.

The rotation of the mandrel I3 is continued until the screw-threads 31 are entirely free of the screw-threads 33. This point may be ascertained beforehand by determining the number of revolutions necessary, or by a slight upward movement of the tubing at the well head during the operation. The mandrel is now moved upwardly to move the packing rings ll upwardly into engagement with the lower extremity of the sleeve l2.

Additional upward movement will expand the packing rings and distort them into a packed-oft position. Any desirable and suitable amount of tension may be placed on the tubing and mandrel to expand the packing rings into a packed-off position. In this manner a very efllcient and complete packing oil is had. As maybe seen in Figure 2 of the drawings, the packing means, when in a packed-oi! position, are in such a position as to be expanded by any fluid pressure present within the well bore. Also, the slip setting collar 33 is disengaged from the threads 31 on the mandrel l3. The disengaging of the collar prevents any force or element present in or about the'device from setting the slips too tightly, and thereby. rendering their disengagement difllcult or deforming the casing.

It will be noted, that the ports 4| and 44 have been uncovered by the hereinbefore described operations, but that the ports 5| remain closed so that fluid may not pass from the bore of the mandrel it through the ports II and 44. While the device is in the position shown in Figure 2, cement is introduced into the bore of the mandrel by any suitable means, and allowed to flow through the bore 58 of the head 41 and open the poppet valve 81, from where the cement flows into the well bore and the surrounding formation.

The next operation is the further clockwise rotation of the mandrel. Since the head 41 and shank 42 are held against rotation by the engagement of the packing rings, the aforesaid rotation of the mandrel l3 will break the joint between the screw-threads 50 and the screw-threads 49. Thus the mandrel it will move upwardly with respect to the shank l2, and the ports 5| will be exposed above the packing ring 52 and the flange 48 with the threads 49 and 50 still in-engagement.

Water. or any other suitable wash-down liquid,

may now be pumped down the bore of the mandrel to pass outwardly through the ports 5i, and upwardly and outwardly through the ports 44 and to the annular space between the housing Hi and the inside wall of the casing A. The washing operation is continued until all of the cement has been washed out of the bore of the tubing and the mandrel and upwardly out the top of the well casing, or this operation may be reversed and the fluid pumped down through the casing and up through the mandrel l3 and tubing. This posifrom the well bore. 3 provided which is quickly and easily set and un set in a well bore regardless of any fiuid'pressure that may be present, and which may be removed tion of the device is shown in the drawings in Figure 3.

Further clockwise rotation of the mandrel will cause the screw-threads 50 to. become completely disengaged from the screw-threads 49. 'Of course,

the screw-threads 31 will continue to screw upwardly into the screw-threads 38. Downward movement of the mandrel will carry the collar II downwardly within the housing III, causing the lower surface of the collar to strike the upper side of the slip actuating collar 33 and thereby drive the collar 33 downwardly,'thus releasing the slips 29. Subsequent upward movement of the tubing and mandrel within the well bore will raise the collar I5 within the housing III,

causing the collar to strike or engage the lower. side of the bushing I8 and raise the housing,-

thereby releasing the packing rings from their drel I 3 may be rotated clockwise until the screwthreads 31 reach the uppermost position of the screw-threads 38. At this point, further rotation.

of the mandrel will cause the collar I5 and the sleeve I IV to rotate, thereby shearing the pin 21 and allowing the sleeve I I to be unscrewed from sleeve II and the collar I 5, may now be removed Thus a pack-oil device is from the well bore in its entirety so as to leave the well bore clean of obstructions; also a portion of said device may be removed from the well bore in the event the device becomes stuck.

In Figures 12 and 13 there has been shown how this structure may be used in what is commonly called a production packer. In many wells it is desirable to insert a packing on the tubing through which the well is produced. This is for the purpose of sealing above the producing sands so that the fluid will be forced to flow through 'the tubing and not around it. It is especially adaptable where the casing above the producing sands has begun to leak, thereby allowing a fluid such as salt water to enter the producing sands;

' however, by using this packer, this flow of fluid may be sealed off from the producing sands.

The structure shown in Figures 12 and 13 is identical to that shown in the rest of the drawings, except that the poppet valve 51 is left off,

' and a perforated bull-nose screen 65 is screwthreadedly attached to the lower end of the head 4-1. The packer is run into the well bore, as is the pack-oil device, to a point above the producing sands; said packer is set in the same manner as the device hereinbefore described. The mandrel may be rotated to open the port 5| so that the mud may be washed out of said suspending assasze tube and device, so as to allow the well to pro-.- duce and flow into the screen 65 and up through the mandrel and tubing, thus providing a pro-.

ducing packer. It is pointed out that when the well begins to flow, the mandrel is rotated in a counterclockwise "direction so as to move the port SI downwardly, thereby closing the same, and allowing said fluid to flow up the tubing. In the event high pressures are encountered. they will act upon the bottom of the packing and will act to seal the packing tighter: said tool may be released and taken out or the well in the same manner as the pack-of! device.

Various changes, alterations and modifications maybe made in the size, shape and arrangement of the herein described elements, within the scope of the appended claims.

What I claim and desire to Patent isz secure by Letters 1.,A well pack ofl device including, a tubular mandrel, a support housing carried by said mandrel, slips carried by said support, a slip actuator collar connected with said mandrel for longituthe sleeve I2. The mandrel I3, along with the dinal movement thereon, and to be set in said slips by upward movement thereof, and a slip actuator collar releasing member connected with said mandrel above the slip actuator collar relative to the slips to release them from engagement.

'2. A well pack-oil device including, a tubular mandrel. a support housing on said mandrel, a J slot in said support, a pin'on said mandrel receivd in said slot, slips carried by said support,-

a slip actuator screw threaded on said mandrel for longitudinal moyement thereon, and a slip releasing member screw threaded on said mandrel for longitudinal movement thereon and for engaging said slip actuator to move it relative to the slips to release the same.

3. A well pack-oil device including, a longitudinal mandrel, means operable by the mandrel for anchoring the device in a well casing. means operable by the mandrel for packing of! the device in a well casing, a valve for shutting of! upward flow through the mandrel, fluid admitting means in said mandrel for admitting washing fluid to the interior of the mandrel above the valve and which means is normally closed, and

' means for moving the mandrel to open the fluid admitting means while the device is anchored and packed oil.

4. A well pack-oil device including, a housing, a mandrel, a slip actuating collar connected to the mandrel, an upwardly tapering face on said collar, slips slidably carried in said housing, said mandrel being moveableupwardly of said housing for setting said collar within said slips to anchor the housing, a rotatable connection to release said mandrel from said actuating collar, a packer carried by. the mandrel, said slip actuating collar being held against upward movement by the slips so that longitudinal movement of the niandrel effects the setting of the thereagainst.

GEORGE GREEN.

packer 

